Zack Greinke, Diamondbacks

The need-to-know: 35 years old. Three years, $104.5 million left on contract

Why your team needs him: He’s the consistency any playoff-bound rotation craves. In the past 11 years, Greinke has thrown at least 200 innings eight times, and his lowest total in that stretch is 158 2/3. He finished second in the NL Cy Young voting in 2015 and fourth in 2017, and he was reliably solid again in 2018, with a 3.21 ERA, 4.63 K/BB and 4.2 bWAR.

The “yeah, but …”: The team that deals for Greinke would be trading for his Age 35, 36 and 37 years, and he’s making more money per year than any other pitcher in baseball. Greinke feels like the type of hurler who has the pitchability (whatever that word means) to be an effective out-getter deep into his 30s, but finding the right combination of money/prospects figures to be tricky.

Madison Bumgarner, Giants

The need-to-know: 29 years old. Free agent after 2019

Why your team needs him: Because he’s Madison freaking Bumgarner, and if your goal is to win the World Series, no pitcher has a better track record in October than MadBum. His 0.25 ERA in 36 career World Series innings (no, not a typo) is the stuff of legend. He’s been pretty good in the regular season, too, with a career 3.03 ERA/3.25 FIP. Yes, he’s missed time with injuries each of the past two seasons, but one was a dirt-bike injury and one was a broken bone, and he returned fully healthy from both. He is the best starting pitcher potentially available this offseason.

The “yeah, but …”: It’s the “potentially available” part that’s tricky. Bumgarner is, along with Buster Posey, the face of the San Francisco franchise, and any team trading for the lefty would almost certainly have to overpay for one year of a starting pitcher. It’s the first year on the job for new GM Farhan Zaidi, and if he’s going to trade his most popular and valuable asset — a reasonable thought, considering the organization’s need to add young talent — he’s going to have to “win” the trade.

Sonny Gray, Yankees

The need-to-know: 29 years old. Arbitration-eligible in 2019, free agent after 2019

Why your team needs him: Because Sonny Gray is too good of a pitcher to perform like he did at Yankee Stadium in 2018, and you want to be the team that benefits from his motivated bounce-back season. Also, because he probably won’t cost nearly as much in prospects as some of the other starters on this list, and he’s worth the risk.

The “yeah, but …”: On one hand, you can look at Gray’s 2018 splits — 6.98 ERA at Yankee Stadium, 3.17 ERA on the road — and say that Gray is a perfect change-of-scenery candidate. On the other hand, it’s fair to wonder WHY he was so bad in the Bronx and wonder if he’s really capable of putting together a full season like did early in his career (2.91 ERA in 64 starts in 2014-15).

Noah Syndergaard, Mets

The need-to-know: 26 years old. Three years of arbitration remaining, free agent after 2021

Why your team needs him: Because Syndergaard is going to win at least one Cy Young award in his career, and you want him wearing your uniform when he gets that first one. Despite being limited to 25 starts in 2018, the big right-hander still finished tied for seventh in the NL in fWAR. Any team that trades for him will be getting his prime years — Age 26, 27 and 28.

The “yeah, but …”: The cost will be high. Like the Giants, the Mets have a new GM in Brodie Van Wagenen, and the pressure will be on him to land a massive haul of talent in return.

Brodie Van Wagenen says there would have to be "very special circumstances for us to even consider" trading Noah Syndergaard. He is part of the Mets' core.

Corey Kluber, Indians

The need-to-know: Kluber, who will be 33 on April 10, has club options for 2020 ($13.5 million) and 2021 ($14 million).

Why your team needs him: Because when guys who have two Cy Young awards (and two third-place finishes) in the past five years become available on the trade market, you do what you can to deal for those guys. The big right-hander has five consecutive seasons of at least 200 innings and 222 strikeouts. He’s not the only member of Cleveland’s rotation reportedly available, either. Carlos Carrasco, who will be 32 on March 21, has a club option for 2020 ($9.5 million), and he’s coming off a season with a 2.94 FIP and 10.8 strikeouts per nine.

The “yeah, but …”: Potential cost, maybe? Kluber has been the model of elite consistency. Age, maybe? But he’s still a couple years younger than Greinke.